Numerous devices have been developed and are being used to traverse piping systems for cleaning, inspection, and or examination of the piping system. For example, such "pipe crawlers" may be equipped with cleaning apparatus suitable for cleaning the inside surfaces of the piping system. Alternatively, the pipe crawler may be fitted with a small camera to allow for visual inspection of the piping system. In still other applications, the pipe crawler may be equipped with sensors to perform any of a wide range of examinations.
One type of pipe crawler design incorporates a plurality of inflatable bladders or sections that are selectively inflated and deflated by a suitable control system. The inflatable sections are designed so that they expand both radially and axially upon inflation. Accordingly, the selective inflation and deflation of the various inflatable bladders causes the pipe crawler to advance or retreat through the pipe section in an inch-worm like fashion. Another type of pipe crawler utilizes a mechanical track drive system to move the pipe crawler through the piping system.
While such pipe crawlers are advantageous in that they allow for the in-situ cleaning, examination, or inspection of piping systems, they are not without their disadvantages. For example, while such pipe crawlers have been used successfully in relatively large-diameter piping systems, it has been difficult to miniaturize the pipe crawlers so that they can be used in smaller diameter piping systems, such as systems having pipes with diameters in the range of 1-3 inches. Even if such pipe crawlers could be miniaturized, problems remain in coming up with a design capable of accommodating different pipe diameters. It has also proven difficult to provide such pipe crawlers with the ability to ascend and descend vertical portions of the piping system. Still other difficulties are associated with guiding the pipe crawler through the various elbow and "tee" joints usually present in every piping system.
Consequently, a need exists for a pipe crawler capable of traversing small-diameter piping systems. Such a pipe crawler should be suitable for use in a piping system having several different diameters and should be capable ascending and descending vertical portions of the piping system. Additional advantages could be realized if the pipe crawler could be selectively navigated through the various "tee" and elbow joints contained in most piping systems.